Aura instruments.

Aura (EOS CH-1) is a multi-national NASA scientific research satellite in orbit around the Earth, studying the Earth's ozone layer, air quality and climate.[2] It is the third major component of the Earth Observing System (EOS) following on Terra (launched 1999) and Aqua (launched 2002). Aura follows on from the Upper Atmosphere Research Satellite (UARS). Aura is a joint mission between NASA, the Netherlands, Finland, and the U.K.[3] The Aura spacecraft is healthy and is expected to operate until at least 2028, possibly beyond, however only two of its four instruments are functioning nominally.[4]

The name "Aura" comes from the Latin word for air. The satellite was launched from Vandenberg Air Force Base on July 15, 2004, aboard a Delta II 7920-10L rocket.

The Aura spacecraft has a mass of about 1,765 kg (3,891 lb). The body is 6.9 m (23 ft) long with the extended single solar panel about 15 m (49 ft) long.

Aura originally flew in a Sun-synchronous orbit, in formation with three other satellites, collectively known as the "A Train"; it is last in the formation. The other satellites in the formation are:

All satellites have an equatorial crossing time at about 1:30 in the afternoon, thus the name 'A (Afternoon) Train'. Since 2023, Aura has been allowed to drift to save fuel.

Mission

As of 2015, there had been 1589 Aura-related journal articles. The scientific findings of these studies address key NASA research objectives related to stratospheric composition, air quality, and climate change.[5]

Aura has suffered some minor, non-mission ending anomalies.

On January 12, 2005, a solar array connector partially "unzipped" losing temperature telemetry and power from part of the solar array. On March 12, 2010, Aura lost power from one-half of one of the 11 solar panels and this was attributed to a Micrometeoroid Orbital Debris (MMOD) strike. These events, and 9 other anomalies in the array regulation electronics (ARE), have resulted in an estimated loss of 33 out of 132 solar strings.[6] Nonetheless, the mission is estimated to have ample power capabilities to supply the mission until fuel runs out.[7][8][9]

A Formatter Multiplexer Unit (FMU) / Solid State Recorder (SSR) anomaly was first detected in December 2007. New symptoms were detected in January 2017 and starting on March 21, 2017, Aura no longer recorded housekeeping data to partition 31.[7]

In December 2016, reaction wheel #3 spun down. It was recovered 10 days later.[7]

On January 31, 2018, the TES instrument was decommissioned due to degrading operations. A mechanical arm on the instrument began stalling intermittently in 2010, affecting TES's ability to collect data continuously. Despite the adaptations of TES operators, the degradation got worse with time and in 2017 the instrument lost operations for approximately half the year. It continues to receive enough power to keep it from getting too cold which could affect the two remaining functioning instruments.[10] Operators initiated a series of End of Life tests of the TES laser that lasted into at least 2022.[11]

Fuel depletion became a problem for the satellite in the 2020s. The final Drag Make-Up (DMU) maneuvers were performed in January 2023 and the final Inclination Adjust Maneuver(IAM) was performed in April 2023 to save remaining fuel for a safe de-orbit. As a result, the spacecraft has started to drift and lose altitude, but it should only lose a few kilometers of altitude by the end of the mission.[4]

As of 2026, insufficient power generation by the solar array is conservatively predicted to be the life-limiting factor for the Aura satellite and instruments by July 2028.[12][4] Predicted re-entry would be 2048.[8][6] In its 2025 "skinny budget" request, the Trump Administration proposed terminating the Aura mission early, however in early 2026 NASA was requesting partners for operations and data collection for Aura, Aqua and Terra.[13]

Instruments

Aura carries four instruments for studies of atmospheric chemistry:

  • HIRDLS — High Resolution Dynamics Limb Sounder — measures infrared radiation from ozone, water vapor, CFCs, methane and nitrogen compounds. Developed jointly with the United Kingdom Natural Environment Research Council. HIRDLS capabilities were compromised at launch when a piece of Kapton film in the instrument came loose and blocked much of the aperture, allowing only a partial view. The blockage prevented certain types of observations and necessitated the development of algorithms to remove the effects due to the blockage. This unanticipated algorithm developmental effort delayed data delivery. The HIRDLS chopper motor stalled on March 17, 2008, and HIRDLS has not produced science since.[14]
  • MLS — Microwave Limb Sounder — measures emissions from ozone, chlorine and other trace gases, and helps to clarify the role of water vapor in global warming. The MLS instrument package is divided into the THz, GHz, and spectrometer modules. The THz module was developed to measure the OH radical in the stratosphere and mesosphere using heterodyne detection of thermal emission. These modules observe emissions across 20 bands. In February 2006, band 13, the primary MLS band for measuring HCl, began to exhibit symptoms of aging and was deactivated to conserve life. It now only makes periodic observations. On August 6, 2013, band 12, which measures N2O, shut down.[15][7]
  • OMI — Ozone Monitoring Instrument — uses ultraviolet and visible radiation to produce daily high-resolution maps. Developed by the Finnish Meteorological Institute and the Netherlands Agency for Aerospace Programmes. In 2007, OMI began to experience a "row anomaly" which affected the quality of the radiance data. The row anomaly has continued to progress since then, with periods of stability.[16]
  • TES — Tropospheric Emission Spectrometer — measured tropospheric ozone in infrared wavelengths, also carbon monoxide, methane and nitrogen oxides. TES's laser A, which was used for retrieving interferometer control, began operating below peak in 2007 but was resurrected to replace laser B which ceased operation in August 2016. Laser A then operated at only 10% power. In 2011, TES observations were shifted from global survey mode, in which it made continuous observations, to special operations mode, wherein it made high sample density observations over specific targets. Furthermore, the TES Interferometer Control System (ICS) motor began stalling in 2015. Each stall took days or weeks to recover from and as of 2018 there had been 19 of them. As a result, in early 2018 the instrument was decommissioned.[5][7][17][18]
Animation of Aura's orbit around Earth. Earth is not shown

See also

References

  1. 1 2 3 4 5 6 "AURA Satellite details 2004-026A NORAD 28376". N2YO. 25 January 2015. Retrieved 25 January 2015.
  2. ↑ Schoeberl, M.R.; Douglass, A.R.; Hilsenrath, E.; Bhartia, P.K.; Beer, R.; Waters, J.W.; Gunson, M.R.; Froidevaux, L.; Gille, J.C.; Barnett, J.J.; Levelt, P.F. (May 31, 2006). "Overview of the EOS aura mission" (PDF). IEEE Transactions on Geoscience and Remote Sensing. 44 (5). IEEE: 1066–1074. Bibcode:2006ITGRS..44.1066S. doi:10.1109/TGRS.2005.861950. eISSN 1558-0644. ISSN 0196-2892. S2CID 2153656. Archived (PDF) from the original on April 14, 2026.
  3. ↑ "Aura" (PDF). Earth Science Reference Handbook. NASA. pp. 101–117. Archived from the original (PDF) on June 23, 2018. Retrieved September 7, 2018.
  4. 1 2 3 "Potential Evolution of the Aura Mission". NASA. May 2025. Archived from the original on June 28, 2026. Retrieved June 2, 2025.
  5. 1 2 Liu, Guosheng (22 June 2015). NASA Earth Science Senior Review 2015 (PDF) (Report). Archived (PDF) from the original on 28 October 2020. Retrieved 17 October 2017.
  6. 1 2 Fischer, Dominic (September 29, 2020). Mission Status for Earth Science Constellation MOWG Meeting EOS Aura (PDF). Earth Science Constellation Mission Operations Working Group (MOWG) meeting. NASA. hdl:2060/20205007514. Archived (PDF) from the original on December 4, 2024. Retrieved July 15, 2021.
  7. 1 2 3 4 5 Fisher, Dominic (June 13, 2017). Mission Status at Aura Science Team MOWG Meeting (PDF). Mission Status for Earth Science Constellation Mission Operations Working Group (MOWG) Meeting. Greenbelt, MD: NASA. hdl:2060/20170005606. Archived (PDF) from the original on July 10, 2026. Retrieved December 13, 2017.
  8. 1 2 Fisher, Dominic (December 6, 2017). Mission Status for Earth Science Constellation MOWG Meeting at KSC: EOS Aura (PDF). Earth Science Constellation Mission Operations Working Group (MOWG) Meeting. Cocoa Beach, FL. hdl:2060/20170011627. Archived (PDF) from the original on June 10, 2025. Retrieved April 5, 2018.
  9. ↑ Fischer, Dominic; Hudson, Chuck (June 12, 2018). Mission Status for Earth Science Constellation MOWG Meeting (PDF). Constellation Mission Operations Working Group (MOWG) Meeting. Sioux Falls, SD: NASA. hdl:2060/20180004066. Archived (PDF) from the original on October 8, 2024. Retrieved September 7, 2018.
  10. ↑ Rasmussen, Carol; Buis, Alan (February 13, 2018). "Farewell to a Pioneering Pollution Sensor" (Press release). NASA/JPL. 2018-031. Archived from the original on March 27, 2026. Retrieved April 5, 2018.
  11. ↑ Fischer, Dominic (May 17, 2022). EOS Aura Mission Status May 2022. Earth Science Constellation Mission Operations Working Group (MOWG) meeting. NASA. hdl:2060/20220006489. Archived from the original on August 13, 2026. Retrieved July 15, 2025.
  12. ↑ "Request for Information (RFI): Terra, Aqua, and Aura (TAA) Missions" (PDF). February 12, 2026 [January 29, 2026]. NNH26ZDA003L. Archived (PDF) from the original on August 13, 2026. Retrieved July 21, 2026.
  13. ↑ Voosen, Paul (May 30, 2025). "Dozens of active and planned NASA spacecraft killed in Trump budget request". Science. doi:10.1126/science.zo6ipdm. eISSN 1095-9203. ISSN 0036-8075. Retrieved July 15, 2025.
  14. ↑ Schoeberl, M (2011). Aura Senior Review (PDF) (Report). Archived (PDF) from the original on 21 January 2022. Retrieved 17 October 2017.
  15. ↑ Livesey, Nathaniel J. "MLS Version 3.3 Level 2 data quality and description document" (PDF). Retrieved 13 December 2017.
  16. ↑ "Background information about the Row Anomaly in OMI". Retrieved 13 December 2017.
  17. ↑ Vandemark, Douglas. "NASA Earth Science Senior Review Subcommittee Report - 2017" (PDF). Retrieved 14 December 2017.
  18. ↑ Fischer, Dominic; Hudson, Chuck (June 12, 2018). Mission Status for Earth Science Constellation MOWG Meeting (PDF). Constellation Mission Operations Working Group (MOWG) Meeting. Sioux Falls, SD: NASA. hdl:2060/20180004066. Archived (PDF) from the original on October 8, 2024. Retrieved July 15, 2021.
allikas: https://en.wikipedia.org/wiki/Aura_(satellite)